[merged mm-stable] mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch removed from -mm tree

[merged mm-stable] mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/memory_hotplug: use pfn math in place of direct struct page manipulation
has been removed from the -mm tree.  Its filename was
     mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Zi Yan <ziy@nvidia.com>
Subject: mm/memory_hotplug: use pfn math in place of direct struct page manipulation
Date: Wed, 13 Sep 2023 16:12:46 -0400

When dealing with hugetlb pages, manipulating struct page pointers
directly can get to wrong struct page, since struct page is not guaranteed
to be contiguous on SPARSEMEM without VMEMMAP.  Use pfn calculation to
handle it properly.

Without the fix, a wrong number of page might be skipped. Since skip cannot be
negative, scan_movable_page() will end early and might miss a movable page with
-ENOENT. This might fail offline_pages(). No bug is reported. The fix comes
from code inspection.

Link: https://lkml.kernel.org/r/20230913201248.452081-4-zi.yan@sent.com
Fixes: eeb0efd071d8 ("mm,memory_hotplug: fix scan_movable_pages() for gigantic hugepages")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memory_hotplug.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/memory_hotplug.c~mm-memory_hotplug-use-pfn-math-in-place-of-direct-struct-page-manipulation
+++ a/mm/memory_hotplug.c
@@ -1689,7 +1689,7 @@ static int scan_movable_pages(unsigned l
 		 */
 		if (HPageMigratable(head))
 			goto found;
-		skip = compound_nr(head) - (page - head);
+		skip = compound_nr(head) - (pfn - page_to_pfn(head));
 		pfn += skip - 1;
 	}
 	return -ENOENT;
_

Patches currently in -mm which might be from ziy@nvidia.com are